driver core: remove fields from struct bus_type

struct bus_type is static everywhere in the kernel.  This moves the
kobject in the structure out of it, and a bunch of other private only to
the driver core fields are now moved to a private structure.  This lets
us dynamically create the backing kobject properly and gives us the
chance to be able to document to users exactly how to use the struct
bus_type as there are no fields they can improperly access.

Thanks to Kay for the build fixes on this patch.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 29 insertions, 1 deletions

diff --git a/drivers/base/base.h b/drivers/base/base.h
index 7e309a49a711..ca6d273064f8 100644
--- a/drivers/base/base.h
+++ b/drivers/base/base.h
@@ -1,6 +1,34 @@
 
-/* initialisation functions */
+/**
+ * struct bus_type_private - structure to hold the private to the driver core portions of the bus_type structure.
+ *
+ * @subsys - the struct kset that defines this bus.  This is the main kobject
+ * @drivers_kset - the list of drivers associated with this bus
+ * @devices_kset - the list of devices associated with this bus
+ * @klist_devices - the klist to iterate over the @devices_kset
+ * @klist_drivers - the klist to iterate over the @drivers_kset
+ * @bus_notifier - the bus notifier list for anything that cares about things
+ * on this bus.
+ * @bus - pointer back to the struct bus_type that this structure is associated
+ * with.
+ *
+ * This structure is the one that is the actual kobject allowing struct
+ * bus_type to be statically allocated safely.  Nothing outside of the driver
+ * core should ever touch these fields.
+ */
+struct bus_type_private {
+        struct kset subsys;
+        struct kset *drivers_kset;
+        struct kset *devices_kset;
+        struct klist klist_devices;
+        struct klist klist_drivers;
+        struct blocking_notifier_head bus_notifier;
+        unsigned int drivers_autoprobe:1;
+        struct bus_type *bus;
+};
+
 
+/* initialisation functions */
 extern int devices_init(void);
 extern int buses_init(void);
 extern int classes_init(void);